Serum carcinoembryonic antigen as a predictive marker for sensitivity to gefitinib in advanced non-small cell lung cancer.

Gefitinib is an inhibitor of epidermal growth factor receptor tyrosine kinase, which has a tumour reducing effect in non-small cell lung cancer (NSCLC). In this study, we retrospectively reviewed the clinical data from 105 patients with advanced NSCLC treated with gefitinib at our department between May 2002 and April 2004. The overall response rate was 27.8% and the median survival time was 9.3 months. Pretreatment characteristics suggested that those with no history of smoking or an elevated serum carcinoembryonic antigen (CEA) level were more likely to be sensitive to gefitinib (P = 0.009). A multivariate analysis indicated good PS (P < 0.0001) and elevated serum CEA level (P = 0.0027) to be independent prognostic factors. These data show that the serum CEA level can be a predictive factor for the efficacy of gefitinib treatment while it is also a prognostic factor for advanced NSCLC patients undergoing this treatment.